Noughts & Crosses/ Tic Tac Toe

#USER: TCG
#Naughts & Crosses (Python 2.7)

import time,random

#Defines Grid
#function is used so that the can be replaced into it's original form when user asks to replay
def grid():
    global g
    g = ["",
    "   --------------------------------",
    "  |          |          |          |",
    "  |     1    |     2    |     3    |",
    "  |          |          |          |",
    "  |--------------------------------|",
    "  |          |          |          |",
    "  |     4    |     5    |     6    |",
    "  |          |          |          |",
    "  |--------------------------------|",
    "  |          |          |          |",
    "  |     7    |     8    |     9    |",
    "  |          |          |          |",
    "   --------------------------------" ]
    print '\n'.join(g),'\n' * 2

#REPLAY GAME / EXIT GAME
def replay():
    while True:
        restart = raw_input("\nWould you like to replay? (yes/no) : ")
        if restart == "yes":
            player1[:] = []
-           player2[:] = []
            grid()
            return 1
        elif restart == "no":
            print '\n'*3, "***** Thanks for playing! *****"
            time.sleep(2)
            raise SystemExit()
        else:
            print '\n' "Incorrect input! Please enter either \"yes\" or \"no\""

#CHECKS IF THERE IS A WINNER
def winner_checker():

    def winner_checker_2(x,x1,x2):

        #All possilble wins
        winner = ["147", "123", "258", "369", "456", "789", "159", "357"]
        if any(all(y in x for y in numbers) for numbers in winner):
            print '\n' * 5, x1, "YOU HAVE WON! GG TO", x2, '\n'
            if replay() == 1:
                return 1

    if winner_checker_2(player1,xplayer,oplayer) == 1:
        return 3
    if winner_checker_2(player2,oplayer,xplayer) == 1:
        return 3

#DISPLAY PLAYER'S MOVE
def display(x,p1,p2,p3,x1,x2,x3,x4):
    if x == move:
        #Replace the spaces with 'x'
        g[p1] = g[p1][:x1] + "\ /" + g[p1][x3:]
        g[p2] = g[p2][:x2] + "x" + g[p2][x4:]
        g[p3] = g[p3][:x1] + "/ \\" + g[p3][x3:]
        print '\n' * 40, '\n'.join(g), '\n'
        return 2

def display2(x,p1,p2,p3,x1,x2,x3,x4):
    if x == move:
        #Replace the spaces with 'o'
        g[p1] = g[p1][:x1] + "---" + g[p1][x3:]
        g[p2] = g[p2][:x2] + "|   |" + g[p2][x4:]
        g[p3] = g[p3][:x1] + "---" + g[p3][x3:]
        print '\n' * 40, '\n'.join(g), '\n'
        return 2

def main_game():
    global player1,player2,oplayer,xplayer,move

    #Header
    print '''
 ----------------------------------------
|                                        |
|            KNOTS & CROSSES             |
|                                        |
 ----------------------------------------''' '\n'

    #Asks for input
    name1 = raw_input("Enter name of player 1 : ")
    name2 = raw_input("Enter name of player 2 : ")

    print'\n' "CHOOSING PLAYERS..."
    time.sleep(1)

    #xplayer is assigned from randomly choosing between name1 & name2
    xplayer = random.choice((name1,name2))

    #Display's who's playing with either noughts and crosses
    print'\n', xplayer, "You are playing with Crosses"
    if name1 != xplayer:
        oplayer = name1
    elif name2 != xplayer:
        oplayer = name2
    print oplayer,"You are playing with Noughts",'\n'

    #print grid
    print "         HERE IS THE GRID :" '\n'
    grid()

    #Initiliaize lists

    player1 = []
    player2 = []

    #PLAYER 1/2 INPUTS

    while True:
        #assigned value to avoid NameError & reset for replay
        loop_count = 0
        for eachplayer in ((xplayer,oplayer)*5):

            move = raw_input("%s It's your turn, enter a number from the grid : " % eachplayer)

            while not move.isdigit() or int(move) < 1 or int(move) > 9:
                move = raw_input("\nInvalid Input, please enter an available number from the grid \n\n"
                                  "%s enter a number from the grid : " % eachplayer)

            while move in player2 or move in player1:
                move = raw_input("\n%s, The space has already been taken \n\n"
                                 "Enter it again, using a number from the grid : " % eachplayer)

            if eachplayer == xplayer:
                #All possible enterable values, which changes the grid accordingly
                if ((display("4",6,7,8,7,8,10,9) or display("1",2,3,4,7,8,10,9) or display("7",10,11,12,7,8,10,9) or
                     display("2",2,3,4,18,19,21,20) or display("5",6,7,8,18,19,21,20) or display("8",10,11,12,18,19,21,20) or
                     display("3",2,3,4,29,30,32,31) or display("6",6,7,8,29,30,32,31) or display("9",10,11,12,29,30,32,31)) == 2):

                    player1.append(move)

            if eachplayer == oplayer:
                #All possible enterable values, which changes the grid accordingly
                if ((display2("4",6,7,8,7,6,10,11) or display2("1",2,3,4,7,6,10,11) or display2("7",10,11,12,7,6,10,11) or
                     display2("2",2,3,4,18,17,21,22) or display2("5",6,7,8,18,17,21,22) or display2("8",10,11,12,18,17,21,22) or
                     display2("3",2,3,4,29,28,32,33) or display2("6",6,7,8,29,28,32,33) or display2("9",10,11,12,29,28,32,33)) == 2):

                    player2.append(move)

            if winner_checker() == 3:
                break

            if loop_count == 8:
                print '\n' * 5, "******* The match was a draw *******" '\n'
                if replay() == 1:
                    break
            loop_count += 1


if __name__ == '__main__':
    main_game()